1. Field of the Invention
The present invention relates to an air pump, and more particularly to a manual air pump with a handle.
2. Description of Related Art
A conventional manual air pump with a handle in accordance with the prior art only has one piston. A single-cylinder air pump, for example, comprises a base member, a cylinder, a shaft, a piston, a handle, a check valve, a discharge tube and a nipple. The base member has a fixed pedal on which the user steps to hold the air pump in place. The cylinder is mounted vertically on the base member. A shaft is moveably mounted in the cylinder. The shaft has a first end moveably mounted in the cylinder and a second end extending out from the cylinder. The piston is mounted on the first end of the shaft, and the handle is mounted on the second end of the shaft so a user can reciprocate the piston in the cylinder. The check valve is mounted on the base member. The discharge tube is mounted on the base member and corresponds to the check valve. The nipple is mounted on a free end of the discharge tube.
The nipple is adapted to connect to an object to be inflated. The piston is moved upward in the cylinder to draw air into the cylinder from outside the pump. The piston is moved downward to pump the air in the cylinder into the object to be inflated. However, the flow rate of the conventional manual air pump with a handle is low. Furthermore, the pressure in the inflated object gradually becomes higher and provides a greater resistance to the air pump, and the user must apply more force to pump air into the inflated object. Consequently, the conventional manual air pump with a handle needs to be advantageously altered.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional.
The main objective of the manual air pump with a handle in accordance with the present invention is to provide an improved manual air pump with a handle.
To achieve the objective, the manual air pump with a handle in accordance with the present invention comprises a base member, a foot switch, an outlet cylinder, an inner cylinder and a pumping assembly. The base member has a wing plate extending laterally from the base member on which the user steps to hold the manual air pump in place during operation of the pump. The foot switch is mounted on the base member. The outlet cylinder is mounted vertically on the base member. The inner cylinder is mounted vertically on the base member inside the outer cylinder. The pumping assembly moveably mounted in the outer cylinder and receives the inner cylinder. Multiple check valves are mounted in the cylinders and the base member to form two stages to pump air into the inflated object in a great quantity when the inflated object is in a low-pressure condition and easily pump compressed air into the inflated object when the inflated object is in a high-pressure condition.